APP and early-onset autosomal dominant Alzheimer disease: To further explore E/I network features in APP/PS1 mice, we incorporated theta–gamma (θ–γ) phase–amplitude coupling (PAC), an E/I metric that strongly relies on hippocampal–cortical inhibitory gamma-aminobutyric acid (GABA)–mediated (GABAergic) network activity.34,35 This measure supports memory36,37 and is impaired in Alzheimer's disease patients38 and animal models.39-41 Finally, to evaluate fE/I as a potential clinical marker of hippocampal–cortical E/I changes in Alzheimer's disease, fE/I features were correlated with θ–γ PAC and epileptiform activity.